[PATCH V4 1/3] of: introduce for_each_matching_node_and_match()

Thomas Petazzoni thomas.petazzoni at free-electrons.com
Wed Nov 21 05:09:08 EST 2012


On Wed, 21 Nov 2012 10:06:16 +0000, Grant Likely wrote:
> On Wed, Nov 21, 2012 at 9:53 AM, Arnd Bergmann <arnd at arndb.de> wrote:
> > On Tuesday 20 November 2012, Stephen Warren wrote:
> >> However, this results in iterating over table twice; the second time
> >> inside of_match_node(). The implementation of for_each_matching_node()
> >> already found the match, so this is redundant. Invent new function
> >> of_find_matching_node_and_match() and macro
> >> for_each_matching_node_and_match() to remove the double iteration,
> >> thus transforming the above code to:
> >>
> >>     for_each_matching_node_and_match(np, table, &match)
> >>
> >> Signed-off-by: Stephen Warren <swarren at nvidia.com>
> >
> > This look useful, but I wonder if the interface would make more sense if you
> > make the last argument to the macro a normal pointer, rather than a
> > pointer-to-pointer. You can take the reference as part of the macro.
> 
> To me that makes for harder to understand code. It *looks* like an
> argument to a normal function call, but it gets changed by the caller.

Agreed. Too much magic is too much.

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com



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